/*
 * YAFFS: Yet Another Flash File System. A NAND-flash specific file system.
 *
 * Copyright (C) 2002-2015 Aleph One Ltd.
 *
 * Created by Charles Manning <charles@aleph1.co.uk>
 *
 * This software is the subject of a Licence Agreement between Aleph One Limited and Hi_Silicon_Huawei_DigiMedia.
 *
 */

#ifndef __YAFFS_GUTS_H__
#define __YAFFS_GUTS_H__

#include "yportenv.h"
#include "sys/statfs.h"

#ifdef __cplusplus
#if __cplusplus
extern "C" {
#endif /* __cplusplus */
#endif /* __cplusplus */


#define YAFFS_OK    1
#define YAFFS_FAIL  0

/*
 * Tnodes form a tree with the tnodes in "levels"
 * Levels greater than 0 hold 8 slots which point to other tnodes.
 * Those at level 0 hold 16 slots which point to chunks in NAND.
 *
 * A maximum level of 8 thust supports files of size up to:
 *
 * 2^(3*MAX_LEVEL+4)
 *
 * Thus a max level of 8 supports files with up to 2^^28 chunks which gives
 * a maximum file size of around 512Gbytees with 2k chunks.
 */
#define YAFFS_NTNODES_LEVEL0        16
#define YAFFS_TNODES_LEVEL0_BITS    4
#define YAFFS_TNODES_LEVEL0_MASK    0xf

#define YAFFS_NTNODES_INTERNAL      (YAFFS_NTNODES_LEVEL0 / 2)
#define YAFFS_TNODES_INTERNAL_BITS  (YAFFS_TNODES_LEVEL0_BITS - 1)
#define YAFFS_TNODES_INTERNAL_MASK  0x7
#define YAFFS_TNODES_MAX_LEVEL      8
#define YAFFS_TNODES_MAX_BITS       (YAFFS_TNODES_LEVEL0_BITS + \
                    YAFFS_TNODES_INTERNAL_BITS * \
                    YAFFS_TNODES_MAX_LEVEL)
#define YAFFS_MAX_CHUNK_ID      ((1 << YAFFS_TNODES_MAX_BITS) - 1)

#define YAFFS_MAX_FILE_SIZE_32      0x7fffffff

/* Constants for YAFFS1 mode */
#define YAFFS_BYTES_PER_SPARE       16
#define YAFFS_BYTES_PER_CHUNK       512
#define YAFFS_CHUNK_SIZE_SHIFT      9
#define YAFFS_CHUNKS_PER_BLOCK      32
#define YAFFS_BYTES_PER_BLOCK   (YAFFS_CHUNKS_PER_BLOCK*YAFFS_BYTES_PER_CHUNK)

#define YAFFS_MIN_YAFFS2_CHUNK_SIZE 1024
#define YAFFS_MIN_YAFFS2_SPARE_SIZE 32



#define YAFFS_ALLOCATION_NOBJECTS   100
#define YAFFS_ALLOCATION_NTNODES    100
#define YAFFS_ALLOCATION_NLINKS     100

#define YAFFS_NOBJECT_BUCKETS       256

#define YAFFS_OBJECT_SPACE      0x40000
#define YAFFS_MAX_OBJECT_ID     (YAFFS_OBJECT_SPACE - 1)

/* Binary data version stamps */
#define YAFFS_SUMMARY_VERSION       1
#define YAFFS_CHECKPOINT_VERSION    7

#ifdef CONFIG_YAFFS_UNICODE
#define YAFFS_MAX_NAME_LENGTH       127
#define YAFFS_MAX_ALIAS_LENGTH      79
#else
#define YAFFS_MAX_NAME_LENGTH       255
#define YAFFS_MAX_ALIAS_LENGTH      159
#endif

#define YAFFS_SHORT_NAME_LENGTH     15

/* Some special object ids for pseudo objects */
#define YAFFS_OBJECTID_ROOT     1
#define YAFFS_OBJECTID_LOSTNFOUND   2
#define YAFFS_OBJECTID_UNLINKED     3
#define YAFFS_OBJECTID_DELETED      4

/* Fake object Id for summary data */
#define YAFFS_OBJECTID_SUMMARY      0x10

/* Pseudo object ids for checkpointing */
#define YAFFS_OBJECTID_CHECKPOINT_DATA  0x20
#define YAFFS_SEQUENCE_CHECKPOINT_DATA  0x21

#define YAFFS_MAX_SHORT_OP_CACHES   20

#define YAFFS_N_TEMP_BUFFERS        6

/* We limit the number attempts at sucessfully saving a chunk of data.
 * Small-page devices have 32 pages per block; large-page devices have 64.
 * Default to something in the order of 5 to 10 blocks worth of chunks.
 */
#define YAFFS_WR_ATTEMPTS       (5*64)

/* Sequence numbers are used in YAFFS2 to determine block allocation order.
 * The range is limited slightly to help distinguish bad numbers from good.
 * This also allows us to perhaps in the future use special numbers for
 * special purposes.
 * EFFFFF00 allows the allocation of 8 blocks/second (~1Mbytes) for 15 years,
 * and is a larger number than the lifetime of a 2GB device.
 */
#define YAFFS_LOWEST_SEQUENCE_NUMBER    0x00001000
#define YAFFS_HIGHEST_SEQUENCE_NUMBER   0xefffff00

/* Special sequence number for bad block that failed to be marked bad */
#define YAFFS_SEQUENCE_BAD_BLOCK    0xffff0000

/* ChunkCache is used for short read/write operations.*/
struct yaffs_cache {
    struct yaffs_obj *object;
    int chunk_id;
    int last_use;
    int dirty;
    int n_bytes;        /* Only valid if the cache is dirty */
    int locked;     /* Can't push out or flush while locked. */
    u8 *data;
};

/* yaffs1 tags structures in RAM
 * NB This uses bitfield. Bitfields should not straddle a u32 boundary
 * otherwise the structure size will get blown out.
 */

struct yaffs_tags {
    u32 chunk_id:20;
    u32 serial_number:2;
    u32 n_bytes_lsb:10;
    u32 obj_id:18;
    u32 ecc:12;
    u32 n_bytes_msb:2;
};

union yaffs_tags_union {
    struct yaffs_tags as_tags;
    u8 as_bytes[8];
};


/* Stuff used for extended tags in YAFFS2 */

enum yaffs_ecc_result {
    YAFFS_ECC_RESULT_UNKNOWN,
    YAFFS_ECC_RESULT_NO_ERROR,
    YAFFS_ECC_RESULT_FIXED,
    YAFFS_ECC_RESULT_UNFIXED
};

enum yaffs_obj_type {
    YAFFS_OBJECT_TYPE_UNKNOWN,
    YAFFS_OBJECT_TYPE_FILE,
    YAFFS_OBJECT_TYPE_SYMLINK,
    YAFFS_OBJECT_TYPE_DIRECTORY,
    YAFFS_OBJECT_TYPE_HARDLINK,
    YAFFS_OBJECT_TYPE_SPECIAL
};

#define YAFFS_OBJECT_TYPE_MAX YAFFS_OBJECT_TYPE_SPECIAL

struct yaffs_ext_tags {
    unsigned chunk_used;    /*  Status of the chunk: used or unused */
    unsigned obj_id;    /* If 0 this is not used */
    unsigned chunk_id;  /* If 0 this is a header, else a data chunk */
    unsigned n_bytes;   /* Only valid for data chunks */

    /* The following stuff only has meaning when we read */
    enum yaffs_ecc_result ecc_result;
    unsigned block_bad;

    /* YAFFS 1 stuff */
    unsigned is_deleted;    /* The chunk is marked deleted */
    unsigned serial_number; /* Yaffs1 2-bit serial number */

    /* YAFFS2 stuff */
    unsigned seq_number;    /* The sequence number of this block */

    /* Extra info if this is an object header (YAFFS2 only) */

    unsigned extra_available;   /* Extra info available if not zero */
    unsigned extra_parent_id;   /* The parent object */
    unsigned extra_is_shrink;   /* Is it a shrink header? */
    unsigned extra_shadows; /* Does this shadow another object? */

    enum yaffs_obj_type extra_obj_type; /* What object type? */

    Y_LOFF_T extra_file_size;       /* Length if it is a file */
    unsigned extra_equiv_id;    /* Equivalent object for a hard link */
};

/* Spare structure for YAFFS1 */
struct yaffs_spare {
    u8 tb0;
    u8 tb1;
    u8 tb2;
    u8 tb3;
    u8 page_status;     /* set to 0 to delete the chunk */
    u8 block_status;
    u8 tb4;
    u8 tb5;
    u8 ecc1[3];
    u8 tb6;
    u8 tb7;
    u8 ecc2[3];
};

/*Special structure for passing through to mtd */
struct yaffs_nand_spare {
    struct yaffs_spare spare;
    int eccres1;
    int eccres2;
};

/* Block data in RAM */

enum yaffs_block_state {
    YAFFS_BLOCK_STATE_UNKNOWN = 0,

    YAFFS_BLOCK_STATE_SCANNING,
    /* Being scanned */

    YAFFS_BLOCK_STATE_NEEDS_SCAN,
    /* The block might have something on it (ie it is allocating or full,
     * perhaps empty) but it needs to be scanned to determine its true
     * state.
     * This state is only valid during scanning.
     * NB We tolerate empty because the pre-scanner might be incapable of
     * deciding
     * However, if this state is returned on a YAFFS2 device,
     * then we expect a sequence number
     */

    YAFFS_BLOCK_STATE_EMPTY,
    /* This block is empty */

    YAFFS_BLOCK_STATE_ALLOCATING,
    /* This block is partially allocated.
     * At least one page holds valid data.
     * This is the one currently being used for page
     * allocation. Should never be more than one of these.
     * If a block is only partially allocated at mount it is treated as
     * full.
     */

    YAFFS_BLOCK_STATE_FULL,
    /* All the pages in this block have been allocated.
     * If a block was only partially allocated when mounted we treat
     * it as fully allocated.
     */

    YAFFS_BLOCK_STATE_DIRTY,
    /* The block was full and now all chunks have been deleted.
     * Erase me, reuse me.
     */

    YAFFS_BLOCK_STATE_CHECKPOINT,
    /* This block is assigned to holding checkpoint data. */

    YAFFS_BLOCK_STATE_COLLECTING,
    /* This block is being garbage collected */

    YAFFS_BLOCK_STATE_DEAD
        /* This block has failed and is not in use */
};

#define YAFFS_NUMBER_OF_BLOCK_STATES (YAFFS_BLOCK_STATE_DEAD + 1)

struct yaffs_block_info {

    s32 soft_del_pages:10;  /* number of soft deleted pages */
    s32 pages_in_use:10;    /* number of pages in use */
    u32 block_state:4;  /* One of the above block states. */
                /* NB use unsigned because enum is sometimes
                 * an int */
    u32 needs_retiring:1;   /* Data has failed on this block, */
                /*need to get valid data off and retire*/
    u32 skip_erased_check:1;/* Skip the erased check on this block */
    u32 gc_prioritise:1;    /* An ECC check or blank check has failed.
                   Block should be prioritised for GC */
    u32 chunk_error_strikes:3;  /* How many times we've had ecc etc
                failures on this block and tried to reuse it */
    u32 has_summary:1;  /* The block has a summary */

    u32 has_shrink_hdr:1;   /* This block has at least one shrink header */
    u32 seq_number;     /* block sequence number for yaffs2 */

};

/* -------------------------- Object structure -------------------------------*/
/* This is the object structure as stored on NAND */

struct yaffs_obj_hdr {
    enum yaffs_obj_type type;

    /* Apply to everything  */
    int parent_obj_id;
    u16 sum_no_longer_used; /* checksum of name. No longer used */
    YCHAR name[YAFFS_MAX_NAME_LENGTH + 1];

    /* The following apply to all object types except for hard links */
    u32 yst_mode;       /* protection */

    u32 yst_uid;
    u32 yst_gid;
    u32 yst_atime;
    u32 yst_mtime;
    u32 yst_ctime;

    /* File size  applies to files only */
    u32 file_size_low;

    /* Equivalent object id applies to hard links only. */
    int equiv_id;

    /* Alias is for symlinks only. */
    YCHAR alias[YAFFS_MAX_ALIAS_LENGTH + 1];

    u32 yst_rdev;   /* stuff for block and char devices (major/min) */

    u32 win_ctime[2];
    u32 win_atime[2];
    u32 win_mtime[2];

    u32 inband_shadowed_obj_id;
    u32 inband_is_shrink;

    u32 file_size_high;
    u32 reserved[1];
    int shadows_obj;    /* This object header shadows the
                specified object if > 0 */

    /* is_shrink applies to object headers written when wemake a hole. */
    u32 is_shrink;

};

/*--------------------------- Tnode -------------------------- */

struct yaffs_tnode {
    struct yaffs_tnode *internal[YAFFS_NTNODES_INTERNAL];
};

/*------------------------  Object -----------------------------*/
/* An object can be one of:
 * - a directory (no data, has children links
 * - a regular file (data.... not prunes :->).
 * - a symlink [symbolic link] (the alias).
 * - a hard link
 */

struct yaffs_file_var {
    Y_LOFF_T file_size;
    Y_LOFF_T scanned_size;
    Y_LOFF_T shrink_size;
    int top_level;
    struct yaffs_tnode *top;
};

struct yaffs_dir_var {
    LOS_DL_LIST children;  /* list of child links */
    LOS_DL_LIST dirty; /* Entry for list of dirty directories */
};

struct yaffs_symlink_var {
    YCHAR *alias;
};

struct yaffs_hardlink_var {
    struct yaffs_obj *equiv_obj;
    u32 equiv_id;
};

union yaffs_obj_var {
    struct yaffs_file_var file_variant;
    struct yaffs_dir_var dir_variant;
    struct yaffs_symlink_var symlink_variant;
    struct yaffs_hardlink_var hardlink_variant;
};

struct yaffs_obj {
    u8 deleted:1;       /* This should only apply to unlinked files. */
    u8 soft_del:1;      /* it has also been soft deleted */
    u8 unlinked:1;      /* An unlinked file.*/
    u8 fake:1;      /* A fake object has no presence on NAND. */
    u8 rename_allowed:1;    /* Some objects cannot be renamed. */
    u8 unlink_allowed:1;
    u8 dirty:1;     /* the object needs to be written to flash */
    u8 valid:1;     /* When the file system is being loaded up, this
                 * object might be created before the data
                 * is available
                 * ie. file data chunks encountered before
                * the header.
                 */
    u8 lazy_loaded:1;   /* This object has been lazy loaded and
                 * is missing some detail */

    u8 defered_free:1;  /* Object is removed from NAND, but is
                 * still in the inode cache.
                 * Free of object is defered.
                 * until the inode is released.
                 */
    u8 being_created:1; /* This object is still being created
                 * so skip some verification checks. */
    u8 is_shadowed:1;   /* This object is shadowed on the way
                 * to being renamed. */

    u8 xattr_known:1;   /* We know if this has object has xattribs
                 * or not. */
    u8 has_xattr:1;     /* This object has xattribs.
                 * Only valid if xattr_known. */

    u8 serial;      /* serial number of chunk in NAND.*/
    u16 sum;        /* sum of the name to speed searching */

    struct yaffs_dev *my_dev;   /* The device I'm on */

    LOS_DL_LIST hash_link; /* list of objects in hash bucket */

    LOS_DL_LIST hard_links;    /* hard linked object chain*/

    /* directory structure stuff */
    /* also used for linking up the free list */
    struct yaffs_obj *parent;
    LOS_DL_LIST siblings;

    /* Where's my object header in NAND? */
    int hdr_chunk;

    int n_data_chunks;  /* Number of data chunks for this file. */

    u32 obj_id;     /* the object id value */

    u32 yst_mode;

    YCHAR short_name[YAFFS_SHORT_NAME_LENGTH + 1];

#ifdef CONFIG_YAFFS_WINCE
    u32 win_ctime[2];
    u32 win_mtime[2];
    u32 win_atime[2];
#else
    u32 yst_uid;
    u32 yst_gid;
    u32 yst_atime;
    u32 yst_mtime;
    u32 yst_ctime;
#endif

    u32 yst_rdev;

    void *my_inode;

    enum yaffs_obj_type variant_type;

    union yaffs_obj_var variant;

};

struct yaffs_obj_bucket {
    LOS_DL_LIST list;
    int count;
};

/* yaffs_checkpt_obj holds the definition of an object as dumped
 * by checkpointing.
 */

struct yaffs_checkpt_obj {
    int struct_type;
    u32 obj_id;
    u32 parent_id;
    int hdr_chunk;
    enum yaffs_obj_type variant_type:3;
    u8 deleted:1;
    u8 soft_del:1;
    u8 unlinked:1;
    u8 fake:1;
    u8 rename_allowed:1;
    u8 unlink_allowed:1;
    u8 serial;
    int n_data_chunks;
    Y_LOFF_T size_or_equiv_obj;
};

/*--------------------- Temporary buffers ----------------
 *
 * These are chunk-sized working buffers. Each device has a few.
 */

struct yaffs_buffer {
    u8 *buffer;
    int in_use;
};

/*----------------- Device ---------------------------------*/

struct yaffs_param {
    const YCHAR *name;

    /*
     * Entry parameters set up way early. Yaffs sets up the rest.
     * The structure should be zeroed out before use so that unused
     * and default values are zero.
     */

    int inband_tags;    /* Use unband tags */
    u32 total_bytes_per_chunk;  /* Should be >= 512, does not need to
                     be a power of 2 */
    int chunks_per_block;   /* does not need to be a power of 2 */
    int spare_bytes_per_chunk;  /* spare area size */
    int start_block;    /* Start block we're allowed to use */
    int end_block;      /* End block we're allowed to use */
    int n_reserved_blocks;  /* Tuneable so that we can reduce
                 * reserved blocks on NOR and RAM. */

    int n_caches;       /* If <= 0, then short op caching is disabled,
                 * else the number of short op caches.
                 */
    int cache_bypass_aligned; /* If non-zero then bypass the cache for
                   * aligned writes.
                   */

    int use_nand_ecc;   /* Flag to decide whether or not to use
                 * NAND driver ECC on data (yaffs1) */
    int tags_9bytes;    /* Use 9 byte tags */
    int no_tags_ecc;    /* Flag to decide whether or not to do ECC
                 * on packed tags (yaffs2) */

    int is_yaffs2;      /* Use yaffs2 mode on this device */

    int empty_lost_n_found; /* Auto-empty lost+found directory on mount */

    int refresh_period; /* How often to check for a block refresh */

    /* Checkpoint control. Can be set before or after initialisation */
    u8 skip_checkpt_rd;
    u8 skip_checkpt_wr;

    int enable_xattr;   /* Enable xattribs */

    int max_objects;    /*
                 * Set to limit the number of objects created.
                 * 0 = no limit.
                */

    /* The remove_obj_fn function must be supplied by OS flavours that
     * need it.
     * yaffs direct uses it to implement the faster readdir.
     * Linux uses it to protect the directory during unlocking.
     */
    void (*remove_obj_fn) (struct yaffs_obj *obj);

    /* Callback to mark the superblock dirty */
    void (*sb_dirty_fn) (struct yaffs_dev *dev);

    /*  Callback to control garbage collection. */
    unsigned (*gc_control_fn) (struct yaffs_dev *dev);

    /* Debug control flags. Don't use unless you know what you're doing */
    int use_header_file_size;   /* Flag to determine if we should use
                     * file sizes from the header */
    int disable_lazy_load;  /* Disable lazy loading on this device */
    int wide_tnodes_disabled;   /* Set to disable wide tnodes */
    int disable_soft_del;   /* yaffs 1 only: Set to disable the use of
                 * softdeletion. */

    int defered_dir_update; /* Set to defer directory updates */

#ifdef CONFIG_YAFFS_AUTO_UNICODE
    int auto_unicode;
#endif
    int always_check_erased;    /* Force chunk erased check always on */

    int disable_summary;
    int disable_bad_block_marking;

};

struct yaffs_driver {
    int (*drv_write_chunk_fn) (struct yaffs_dev *dev, unsigned int nand_chunk,
                   const u8 *data, unsigned int data_len,
                   const u8 *oob, unsigned int oob_len);
    int (*drv_read_chunk_fn) (struct yaffs_dev *dev, unsigned int nand_chunk,
                   u8 *data, unsigned int data_len,
                   u8 *oob, unsigned int oob_len,
                   enum yaffs_ecc_result *ecc_result);
    int (*drv_erase_fn) (struct yaffs_dev *dev, int block_no);
    int (*drv_mark_bad_fn) (struct yaffs_dev *dev, int block_no);
    int (*drv_check_bad_fn) (struct yaffs_dev *dev, int block_no);
    int (*drv_initialise_fn) (struct yaffs_dev *dev);
    int (*drv_deinitialise_fn) (struct yaffs_dev *dev);
};

struct yaffs_tags_handler {
    int (*write_chunk_tags_fn) (struct yaffs_dev *dev,
                    int nand_chunk, const u8 *data,
                    const struct yaffs_ext_tags *tags);
    int (*read_chunk_tags_fn) (struct yaffs_dev *dev,
                   int nand_chunk, u8 *data,
                   struct yaffs_ext_tags *tags);

    int (*query_block_fn) (struct yaffs_dev *dev, int block_no,
                   enum yaffs_block_state *state,
                   u32 *seq_number);
    int (*mark_bad_fn) (struct yaffs_dev *dev, int block_no);
};

struct yaffs_dev {
    struct yaffs_param param;
    struct yaffs_driver drv;
    struct yaffs_tags_handler tagger;

    /* Context storage. Holds extra OS specific data for this device */

    void *os_context;
    void *driver_context;

    LOS_DL_LIST dev_list;

    int ll_init;
    /* Runtime parameters. Set up by YAFFS. */
    int data_bytes_per_chunk;

    /* Non-wide tnode stuff */
    u16 chunk_grp_bits; /* Number of bits that need to be resolved if
                 * the tnodes are not wide enough.
                 */
    u16 chunk_grp_size; /* == 2^^chunk_grp_bits */

    /* Stuff to support wide tnodes */
    u32 tnode_width;
    u32 tnode_mask;
    u32 tnode_size;

    /* Stuff for figuring out file offset to chunk conversions */
    u32 chunk_shift;    /* Shift value */
    u32 chunk_div;      /* Divisor after shifting: 1 for 2^n sizes */
    u32 chunk_mask;     /* Mask to use for power-of-2 case */

    int is_mounted;
    int read_only;
    int is_checkpointed;

    /* Stuff to support block offsetting to support start block zero */
    int internal_start_block;
    int internal_end_block;
    int block_offset;
    int chunk_offset;

    /* Runtime checkpointing stuff */
    int checkpt_page_seq;   /* running sequence number of checkpt pages */
    int checkpt_byte_count;
    int checkpt_byte_offs;
    u8 *checkpt_buffer;
    int checkpt_open_write;
    int blocks_in_checkpt;
    int checkpt_cur_chunk;
    int checkpt_cur_block;
    int checkpt_next_block;
    int *checkpt_block_list;
    int checkpt_max_blocks;
    u32 checkpt_sum;
    u32 checkpt_xor;

    int checkpoint_blocks_required; /* Number of blocks needed to store
                     * current checkpoint set */

    /* Block Info */
    struct yaffs_block_info *block_info;
    u8 *chunk_bits;     /* bitmap of chunks in use */
    u8 block_info_alt:1;    /* allocated using alternative alloc */
    u8 chunk_bits_alt:1;    /* allocated using alternative alloc */
    int chunk_bit_stride;   /* Number of bytes of chunk_bits per block.
                 * Must be consistent with chunks_per_block.
                 */

    int n_erased_blocks;
    int alloc_block;    /* Current block being allocated off */
    u32 alloc_page;
    int alloc_block_finder; /* Used to search for next allocation block */

    /* Object and Tnode memory management */
    void *allocator;
    int n_obj;
    int n_tnodes;

    int n_hardlinks;

    struct yaffs_obj_bucket obj_bucket[YAFFS_NOBJECT_BUCKETS];
    u32 bucket_finder;

    int n_free_chunks;

    /* Garbage collection control */
    u32 *gc_cleanup_list;   /* objects to delete at the end of a GC. */
    u32 n_clean_ups;

    unsigned has_pending_prioritised_gc;    /* We think this device might
                        have pending prioritised gcs */
    unsigned gc_disable;
    unsigned gc_block_finder;
    unsigned gc_dirtiest;
    unsigned gc_pages_in_use;
    unsigned gc_not_done;
    unsigned gc_block;
    unsigned gc_chunk;
    unsigned gc_skip;
    struct yaffs_summary_tags *gc_sum_tags;

    /* Special directories */
    struct yaffs_obj *root_dir;
    struct yaffs_obj *lost_n_found;

    int buffered_block; /* Which block is buffered here? */
    int doing_buffered_block_rewrite;

    struct yaffs_cache *cache;
    int cache_last_use;

    /* Stuff for background deletion and unlinked files. */
    struct yaffs_obj *unlinked_dir; /* Directory where unlinked and deleted
                     files live. */
    struct yaffs_obj *del_dir;  /* Directory where deleted objects are
                    sent to disappear. */
    struct yaffs_obj *unlinked_deletion;    /* Current file being
                            background deleted. */
    int n_deleted_files;    /* Count of files awaiting deletion; */
    int n_unlinked_files;   /* Count of unlinked files. */
    int n_bg_deletions; /* Count of background deletions. */

    /* Temporary buffer management */
    struct yaffs_buffer temp_buffer[YAFFS_N_TEMP_BUFFERS];
    int max_temp;
    int temp_in_use;
    int unmanaged_buffer_allocs;
    int unmanaged_buffer_deallocs;

    /* yaffs2 runtime stuff */
    unsigned seq_number;    /* Sequence number of currently
                    allocating block */
    unsigned oldest_dirty_seq;
    unsigned oldest_dirty_block;

    /* Block refreshing */
    int refresh_skip;   /* A skip down counter.
                 * Refresh happens when this gets to zero. */

    /* Dirty directory handling */
    LOS_DL_LIST dirty_dirs;    /* List of dirty directories */

    /* Summary */
    int chunks_per_summary;
    struct yaffs_summary_tags *sum_tags;

    /* Statistics */
    u32 n_page_writes;
    u32 n_page_reads;
    u32 n_erasures;
    u32 n_bad_queries;
    u32 n_bad_markings;
    u32 n_erase_failures;
    u32 n_gc_copies;
    u32 all_gcs;
    u32 passive_gc_count;
    u32 oldest_dirty_gc_count;
    u32 n_gc_blocks;
    u32 bg_gcs;
    u32 n_retried_writes;
    u32 n_retired_blocks;
    u32 n_ecc_fixed;
    u32 n_ecc_unfixed;
    u32 n_tags_ecc_fixed;
    u32 n_tags_ecc_unfixed;
    u32 n_deletions;
    u32 n_unmarked_deletions;
    u32 refresh_count;
    u32 cache_hits;
    u32 tags_used;
    u32 summary_used;

};

/* The CheckpointDevice structure holds the device information that changes
 *at runtime and must be preserved over unmount/mount cycles.
 */
struct yaffs_checkpt_dev {
    int struct_type;
    int n_erased_blocks;
    int alloc_block;    /* Current block being allocated off */
    u32 alloc_page;
    int n_free_chunks;

    int n_deleted_files;    /* Count of files awaiting deletion; */
    int n_unlinked_files;   /* Count of unlinked files. */
    int n_bg_deletions; /* Count of background deletions. */

    /* yaffs2 runtime stuff */
    unsigned seq_number;    /* Sequence number of currently
                 * allocating block */

};

struct yaffs_checkpt_validity {
    int struct_type;
    u32 magic;
    u32 version;
    u32 head;
};

struct yaffs_shadow_fixer {
    int obj_id;
    int shadowed_id;
    struct yaffs_shadow_fixer *next;
};

/* Structure for doing xattr modifications */
struct yaffs_xattr_mod {
    int set;        /* If 0 then this is a deletion */
    const YCHAR *name;
    const void *data;
    int size;
    int flags;
    int result;
};

/*----------------------- YAFFS Functions -----------------------*/

int yaffs_guts_initialise(struct yaffs_dev *dev);
void yaffs_deinitialise(struct yaffs_dev *dev);

int yaffs_get_n_free_chunks(struct yaffs_dev *dev);

int yaffs_rename_obj(struct yaffs_obj *old_dir, const YCHAR * old_name,
             struct yaffs_obj *new_dir, const YCHAR * new_name);

int yaffs_unlinker(struct yaffs_obj *dir, const YCHAR * name);
int yaffs_del_obj(struct yaffs_obj *obj);
struct yaffs_obj *yaffs_retype_obj(struct yaffs_obj *obj,
                   enum yaffs_obj_type type);


int yaffs_get_obj_name(struct yaffs_obj *obj, YCHAR * name, int buffer_size);
Y_LOFF_T yaffs_get_obj_length(struct yaffs_obj *obj);
int yaffs_get_obj_inode(struct yaffs_obj *obj);
unsigned yaffs_get_obj_type(struct yaffs_obj *obj);
int yaffs_get_obj_link_count(struct yaffs_obj *obj);

/* File operations */
long yaffs_file_rd(struct yaffs_obj *obj, u8 * buffer, Y_LOFF_T offset,
          int n_bytes);
int yaffs_wr_file(struct yaffs_obj *obj, const u8 * buffer, Y_LOFF_T offset,
          int n_bytes, int write_trhrough);
int yaffs_resize_file(struct yaffs_obj *obj, Y_LOFF_T new_size);

struct yaffs_obj *yaffs_create_file(struct yaffs_obj *parent,
                    const YCHAR *name, u32 mode, u32 uid,
                    u32 gid);

int yaffs_flush_file(struct yaffs_obj *in,
             int update_time,
             int data_sync,
             int discard_cache);

/* Flushing and checkpointing */
void yaffs_flush_whole_cache(struct yaffs_dev *dev, int discard);

int yaffs_checkpoint_save(struct yaffs_dev *dev);
int yaffs_checkpoint_restore(struct yaffs_dev *dev);

/* Directory operations */
struct yaffs_obj *yaffs_create_dir(struct yaffs_obj *parent, const YCHAR *name,
                   u32 mode, u32 uid, u32 gid);
struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *the_dir,
                     const YCHAR *name);
struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number);

/* Link operations */
struct yaffs_obj *yaffs_link_obj(struct yaffs_obj *parent, const YCHAR *name,
                 struct yaffs_obj *equiv_obj);

struct yaffs_obj *yaffs_get_equivalent_obj(struct yaffs_obj *obj);

/* Symlink operations */
struct yaffs_obj *yaffs_create_symlink(struct yaffs_obj *parent,
                       const YCHAR *name, u32 mode, u32 uid,
                       u32 gid, const YCHAR *alias);
YCHAR *yaffs_get_symlink_alias(struct yaffs_obj *obj);

/* Special inodes (fifos, sockets and devices) */
struct yaffs_obj *yaffs_create_special(struct yaffs_obj *parent,
                       const YCHAR *name, u32 mode, u32 uid,
                       u32 gid, u32 rdev);

int yaffs_set_xattrib(struct yaffs_obj *obj, const YCHAR *name,
              const void *value, int size, int flags);
int yaffs_get_xattrib(struct yaffs_obj *obj, const YCHAR *name, void *value,
              int size);
int yaffs_list_xattrib(struct yaffs_obj *obj, char *buffer, int size);
int yaffs_remove_xattrib(struct yaffs_obj *obj, const YCHAR *name);

/* Special directories */
struct yaffs_obj *yaffs_root(struct yaffs_dev *dev);
struct yaffs_obj *yaffs_lost_n_found(struct yaffs_dev *dev);

void yaffs_handle_defered_free(struct yaffs_obj *obj);

void yaffs_update_dirty_dirs(struct yaffs_dev *dev);

int yaffs_bg_gc(struct yaffs_dev *dev, unsigned urgency);

/* Debug dump  */
int yaffs_dump_obj(struct yaffs_obj *obj);

void yaffs_guts_test(struct yaffs_dev *dev);
int yaffs_guts_ll_init(struct yaffs_dev *dev);


/* A few useful functions to be used within the core files*/
void yaffs_chunk_del(struct yaffs_dev *dev, int chunk_id, int mark_flash,
             int lyn);
int yaffs_check_ff(u8 *buffer, int n_bytes);
void yaffs_handle_chunk_error(struct yaffs_dev *dev,
                  struct yaffs_block_info *bi);

u8 *yaffs_get_temp_buffer(struct yaffs_dev *dev);
void yaffs_release_temp_buffer(struct yaffs_dev *dev, u8 *buffer);

struct yaffs_obj *yaffs_find_or_create_by_number(struct yaffs_dev *dev,
                         int number,
                         enum yaffs_obj_type type);
int yaffs_put_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
                int nand_chunk, int in_scan);
void yaffs_set_obj_name(struct yaffs_obj *obj, const YCHAR *name);
void yaffs_set_obj_name_from_oh(struct yaffs_obj *obj,
                const struct yaffs_obj_hdr *oh);
void yaffs_add_obj_to_dir(struct yaffs_obj *directory, struct yaffs_obj *obj);
YCHAR *yaffs_clone_str(const YCHAR *str);
void yaffs_link_fixup(struct yaffs_dev *dev, LOS_DL_LIST *hard_list);
void yaffs_block_became_dirty(struct yaffs_dev *dev, int block_no);
int yaffs_update_oh(struct yaffs_obj *in, const YCHAR *name,
            int force, int is_shrink, int shadows,
            struct yaffs_xattr_mod *xop);
void yaffs_handle_shadowed_obj(struct yaffs_dev *dev, int obj_id,
                   int backward_scanning);
int yaffs_check_alloc_available(struct yaffs_dev *dev, int n_chunks);
struct yaffs_tnode *yaffs_get_tnode(struct yaffs_dev *dev);
struct yaffs_tnode *yaffs_add_find_tnode_0(struct yaffs_dev *dev,
                       struct yaffs_file_var *file_struct,
                       u32 chunk_id,
                       struct yaffs_tnode *passed_tn);

int yaffs_do_file_wr(struct yaffs_obj *in, const u8 *buffer, Y_LOFF_T offset,
             int n_bytes, int write_trhrough);
void yaffs_resize_file_down(struct yaffs_obj *obj, Y_LOFF_T new_size);
void yaffs_skip_rest_of_block(struct yaffs_dev *dev);

int yaffs_count_free_chunks(struct yaffs_dev *dev);

struct yaffs_tnode *yaffs_find_tnode_0(struct yaffs_dev *dev,
                       struct yaffs_file_var *file_struct,
                       u32 chunk_id);

u32 yaffs_get_group_base(struct yaffs_dev *dev, struct yaffs_tnode *tn,
             unsigned pos);

int yaffs_is_non_empty_dir(struct yaffs_obj *obj);

int yaffs_guts_format_dev(struct yaffs_dev *dev);

void yaffs_addr_to_chunk(struct yaffs_dev *dev, Y_LOFF_T addr,
                int *chunk_out, u32 *offset_out);
/*
 * Marshalling functions to get Y_LOFF_T file sizes into aand out of
 * object headers.
 */
void yaffs_oh_size_load(struct yaffs_obj_hdr *oh, Y_LOFF_T fsize);
Y_LOFF_T yaffs_oh_to_size(struct yaffs_obj_hdr *oh);
Y_LOFF_T yaffs_max_file_size(struct yaffs_dev *dev);

/*
 * Debug function to count number of blocks in each state
 * NB Needs to be called with correct number of integers
 */

void yaffs_count_blocks_by_state(struct yaffs_dev *dev, int bs[10]);

int yaffs_find_chunk_in_file(struct yaffs_obj *in, int inode_chunk,
                    struct yaffs_ext_tags *tags);


#ifdef __cplusplus
#if __cplusplus
}
#endif /* __cplusplus */
#endif /* __cplusplus */

#endif /* __YAFFS_GUTS_H__ */
